Table 4.

Effect of storage on the physicochemical properties of optimized STZ-MMs formulations (MM-8 and MM-11).

Formula	Storage period	SM (mg/mL)	PS (nm)	PDI	ZP (mV)
MM-8	Fresh	7.79 ± 0.17	15.87 ± 0.71	0.249 ± 0.04	28.95 ± 4.38
	1 Month	7.72 ± 0.28	15.99 ± 0.17	0.250 ± 0.01	28.12 ± 2.93
	2 Months	7.69 ± 0.15	16.02 ± 0.01	0.249 ± 0.05	28.80 ± 1.99
	3 Months	7.64 ± 0.25	16.02 ± 0.33	0.247 ± 0.02	25.10 ± 4.10
	6 Months	7.61 ± 0.37	16.04 ± 0.23	0.249 ± 0.04	25.21 ± 0.76
MM-11	Fresh	7.59 ± 0.16	16.39 ± 0.04	0.234 ± 0.04	23.33 ± 1.17
	1 Month	7.53 ± 0.08	16.38 ± 0.08	0.239 ± 0.07	25.20 ± 1.85
	2 Months	7.56 ± 0.14	16.47 ± 0.45	0.242 ± 0.03	25.00 ± 2.83
	3 Months	7.51 ± 0.12	16.52 ± 0.33	0.247 ± 0.06	26.20 ± 4.53
	6 Months	7.25 ± 0.31	16.83 ± 0.39	0.271 ± 0.04	25.70 ± 0.42

S_M: solubility of STZ in MMs; PS: particle size; PDI: polydispersity index; ZP: zeta potential.